LIVER DISTOME. 275 



contained are brownish in colour in the anterior and pale yellow in 

 the posterior parts of it. They measure 0,022-0,027 mm. in length 

 and 0,014-0,015 mm. in breadth. 



This species may be distinguished from other distomes which 

 are known to occur in the liver of the cat by the following charac- 

 teristics : 



1) The absence of spines on the surface of body in the fully 

 grown state. Metorchis trunccttus and Opistliorchis noverca have fine 

 spines on the surface of body, while the distome obtained from my 

 experiments has no spines when fully grown. 



2) The ramification of testes. Opistliorchis felineus and Metorchis 

 albidus have simply lobate testes, while in the present species they 

 are distinctly branched. 



3) The continuous vitellaria. Opistliorchis felineus and Metorchis 

 truncatus have discontinuous vitellaria composed of several groups of 

 follicles, while the present species has continuous vitellaria. 



In spite of the small size of the specimens obtained from my 

 experiments, I believe, on the basis of above grounds, that they all 

 belong to Clonorchis endemicus, and that the fishes mentioned are 

 intermediate hosts of the parasite. 



It is very probable that the fishes which contain the encysted 

 distomes are secondary intermediate hosts of the parasite. The first 

 intermediate host and the way in which the fishes are infected require 

 further investigation. 



Recently I made some observations in Yanaidzu, Miyagi Prefecture, 

 and in Kinohama and Iso, Shiga Prefecture, where hepatic distomi- 

 asis are also known to occur, and I found that various fishes contain 

 the above described cyst distome in their muscle. 



According to my observations the following species of fishes contain 

 the cyst distome in question : 



(1) Leucogobio gïtntheri. 



(2) Pseudorasbora parva. 



